Firefox 17.0.1 release with which Mozilla aimed to fix font rendering issue actually turned out to fix another major bug where cookie exceptions were never saved to the browser. 17.0.1 version has been released and available via update and on Firefox website for download. To upgrade to this version from help menu select about Firefox dialog and once Firefox downloads the update restart the browser to apply it.

What’s fixed in Firefox 17.0.1

Font rendering issue in Firefox 17.0 (bug 814101).

Reverted user agent change causing some website incompatibilities.

Leaving Private Browsing with Social API enabled should reset social components (814554).